Nonfiction review: Connected

NONFICTION

Fans of the British novelist E.M. Forster, who exhorted his readers to "Only connect," should be especially pleased with Nicholas A. Christakis and James H. Fowler's fascinating new book, "Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives." Most of us are far more extensively connected than we realize.

"In the vast fabric of humanity, each person is connected to his friends, family, co-workers, and neighbors, but these people are in turn connected to their friends, family, co-workers, and neighbors, and so on endlessly into the distance, until everyone on earth is connected (pretty much) to everybody else, one way or another," write Christakis and Fowler.

In fact, studies have shown that each of us is separated by only six degrees from everybody else in the world.

But Christakis (a Harvard University professor of sociology, medicine and health care policy) and Fowler (a political-science professor at the University of California at San Diego) suggest that although our interconnectedness reaches around the planet, our ability to influence others doesn't.

"Our own research has shown that the spread of influence in social networks obeys what we call the Three Degrees of Influence Rule," they write. "Everything we do or say tends to ripple through our network, having an impact on our friends (first degree), our friends' friends (two degrees), and even our friends' friends' friends (three degrees)."

Beyond that third degree, the influence dissipates. Within those three degrees, though, you exercise a powerful influence. And they influence you.

Your friend's friend gained weight? Brace yourself: You might, too. "Obesity is contagious," Christakis and Fowler write, and it spreads within social networks like a virus during an epidemic.

And happiness? "We found that each happy friend a person has increases that person's probability of being happy by about 9 percent," they write. "Each unhappy friend decreases it by 7 percent."

Loneliness also is contagious, it turns out. "[Y]ou are about 52 percent more likely to be lonely if a person you are directly connected to (at one degree of separation) is lonely," Christakis and Fowler write. "The effect for people at two degrees of separation is 25 percent, and for people at three degrees of separation, it is about 15 percent." (In keeping with the Three Degrees of Influence Rule, "the effect disappears" at four degrees of separation.)

There's a real pleasure to be had from reading books that reveal unexpected patterns in our everyday lives. They can even help expand your circle of friends, if you have a good head for figures. ("Nice to meet you. My name's Fred, and I have good news: I'm happy, and that could increase your own prospects of happiness by as much as 9 percent if you become my friend.")

But Christakis and Fowler are interested in something far more significant than intriguing trivia. Network science offers powerful practical applications, they argue. It can help fight the spread of sexually transmitted diseases and help curb smoking, for example.

It also could create more effective immunization strategies (a timely topic, given global fears about the swine flu pandemic). One option, Christakis and Fowler suggest, "is to immunize the acquaintances of randomly selected individuals."

Why? "[P]eople with many links are more likely to be nominated as acquaintances than are people with few. In fact, the same level of protection can be achieved by immunizing roughly 30 percent of the people identified by this method than would otherwise be obtained if we immunized 99 percent of the population at random!"

It's not just the practical applications that will make social networking an important field to study in the future. The sheer size and complexity of online social networking is already making it central to many people's daily lives, and it's still in its infancy. Facebook now has more than 300 million active users worldwide, for example.

And when developers for the online game World of Warcraft introduced a relatively contained, contagious disease into its virtual world in 2005, it sparked an online pandemic, "rapidly killing hundreds of thousands of weaker players," Christakis and Fowler write. A week later, the damage was so severe programmers had to reboot the servers to put an end to the crisis.

Which raises the question: If an online avatar gains weight, will the avatars of his friends and his friends' friends gain weight as well? And if they do, does the Three Degrees of Influence Rule apply?

Doug Childers is a Richmond writer and edits WAG, a literary Web site at http://www.thewag.net.